The invention relates to a method for repairing a leak in a sub-soil construction and/or a geological structure or a construction comprising a geological material. The invention further relates to the use of a liquid nutrient composition.
The Dutch patent 1 022 510 describes a method for closing a leak in a subterranean construction by applying a nutrient for bacteria such that the leak is closed by bacterial growth. Optionally salt and hydroxide solutions may be applied to be precipitated in or near the leak. It has been found difficult to control such method.
In GB-A 2 222 420, bacteria are used to enhance oil recovery from an oil producing reservoir. Spores of specific bacteria need to be introduced into the oil producing reservoir. It is disclosed to use bacteria to repair a leak in geological structure or a construction comprising a geological material.
In the method of GB-A 2 222 420 permeability around the oil reservoir is altered by growth of biomass and formation of exopolymers. It is not disclosed in GB-A 2 222 420 to release mineral particles upstream of a leak, to allow the particles to migrate to the leak and to allow the mineral particles to settle in biomass formed by the bacteria. The present inventors have concluded that biomass and exopolymers are only effective for a relatively short-time span, as the polymers are biodegradable and/or the micro-organism may whither once administration of nutrients is stopped.
It is an object of the present invention to provide a novel method for repairing a leak in a geological structure, a sub-soil construction and/or a construction comprising a geological material.
In particular it is an object to provide such method, wherein the water permeability in the structure is decreased.
One or more other objects which may be solved in accordance with the invention are apparent from the present description and/or claims